Hey, thanks for you comment, at first I wanted to change tue blue color for the armor but I realized a gray armor bar on a gray background wasn't the best choice !
I've quickly implemented a tooltip system, you can hover on some things with your mouse, so if you hover the armor icon you see that it is removed the next turn. In roguelike deckbuilder games the armor never last more than 1 turn, that's why I didn't made it more obvious, in future projects I will pay more attention on details like this :p